The invention relates to a serial port testing method and system of a computer. The serial port testing method of the computer includes receiving configured dynamic strategies; detecting whether dynamic strategies are effective or not, if yes, testing serial ports according to the dynamic strategies, and testing the serial ports according to defaulted strategies if not; detecting whether the serial ports work normally or not, if not, performing diagnostic test, recording event logs generated by the diagnostic test, and recording the results of the serial port testing, if yes, stopping the serial port testing and recording the serial port testing results. By the serial port testing method and system, when the serial ports work abnormally, diagnostic testing is performed so as to analyze and locate faults, fault diagnosis is realized, and the event logs generated by the diagnostic testing can be recorded; successive analysis according to the event logs is facilitated, and performance is optimized; testing is performed according to the dynamic strategies, so that corresponding strategy files can be configured according to different control chips, and flexible configuration is realized.